Our study demonstrates that regional anesthesia is associated with a higher rate of acute postoperative urinary retention following placement of a midurethral sling compared to non-regional modes in an ambulatory setting. The choice of surgical anesthesia often involves a balanced discussion between a patient, anesthesiologist, and surgeon, and this information may help to inform patients’ postoperative expectations.
Studies in the urologic and urogynecologic literature have been inconsistent concerning the role of anesthesia in acute postoperative urinary retention in anti-incontinence procedures in women. Kleeman et al. prospectively followed 90 women following surgery for prolapse or incontinence and found no differences in urinary retention rates between women receiving general, regional or local anesthesia. Murphy et al. conducted a retrospective cohort study of 173 women receiving tension-free vaginal tape placement, and concluded that anesthesia type did not predict post-operative voiding dysfunction; however, the authors included women who received regional and local anesthesia together in one group which may have decreased any effect of regional anesthesia on postoperative urinary retention. Duckett et al. performed a prospective cohort study of 500 women who underwent TVT placement and found that general anesthesia was predictive of early postoperative voiding dysfunction; however, only 6% of the patients received general anesthesia. Barron et al. performed a retrospective review of 119 patients undergoing outpatient TVT with or without concomitant surgeries who were discharged on the same day of surgery. They found no significant difference in need for catheterization among patients who received spinal anesthesia compared to general and local with sedation. In this study, 18% of the women received spinal anesthesia, 18% received local with sedation, and 64% received general anesthesia. In the above studies, regional anesthesia was not analyzed as the primary exposure.
The data on regional anesthesia and its effect on acute postoperative urinary retention is more consistent in other fields. Spinal anesthesia has been shown to increase rates of urinary retention in orthopaedic, podiatric, and hernia surgery. (13
) Lamonerie et al. used ultrasonagrophy to diagnose immediate postoperative urinary retention in the recovery room by following 177 patients in a Paris Hospital. Spinal anesthesia conferred the most risk of urinary retention followed by duration of surgery and age. Van Veen et al. performed a randomized trial of 100 patients undergoing inguinal hernia repair to either spinal or local anesthesia. They found significantly lower rates of postopertive urinary retention in patients receiving local anesthesia. Casati et al. randomized 120 patients undergoing arthroscopic knee surgery to intravenous anesthesia, spinal anesthesia, or local sciatic-femoral nerve block. The authors concluded that peripheral analgesia is preferable to spinal anesthesia to minimize postoperative urinary retention. Kamphius et al. demonstrated a measurable interruption in the micturition reflex following spinal anesthesia. In this study, 20 men undergoing elective orthopaedic surgery on lower limbs had interval cystometry performed at capacity and compared detrusor function to ankle, knee, and hip motor function. They found that motor blockade following bupivicaine spinals lasted 148 ± 76 minutes compared to detrusor blockade of 462 ± 61 minutes. The authors also noted that the detrusor blockade continued until the spinal anesthetic regressed above the S3 nerve.
When we examined the difference between non-regional types of anesthesia, specifically GETA vs. LMA, we noted differences in the rates of acute post-operative urinary retention. One explanation for the higher rates of acute urinary retention in the GETA group may be explained by the use of anticholinergics (atropine and glycopyrrolate) during the reversal of anesthesia and prior to extubation. Glycopyrrolate is commonly used to dry oral secretions and reverse muscle relaxants prior to endotracheal extubation. Women undergoing non-regional anesthesia with LMA are generally not given anthicholinergics at our institution. Glycopyrrolate has a half-life of 1.8 hours and has been associated with urinary retention following other outpatient procedures. (20
Our study is limited by the retrospective design. It is possible that our results were influenced by selection bias, in which women who had regional anesthesia were at higher risk for retention. However, when we adjusted for known risk factors for retention including age, BMI, and previous gynecologic surgery, our findings did not change. Also, we were unable to assess the possibility of residual anesthetic affects in the immediate postoperative period at the time of the TOV. It is possible that detrusor blockade was still present at the time of the TOV despite the return of motor neurons that allowed ambulation. In addition, we do not have data regarding a woman’s satisfaction with her choice of anesthesia or overall experience with or without short-term Foley catheter drainage. Although we were not able to assess patient satisfaction between regional and non-regional anesthesia, we were able record pain scores immediately prior to discharge home and found there was no difference between groups. Also, it is not our practice to routinely measure maximum detrusor pressure on all urodynamic testing and therefore do not have data regarding this potential risk factor for retention. Consistent with others (5
) we found a low rate of long-term sequalae of acute postoperative urinary retention. Only one woman required repeat operative intervention for prolonged urinary retention.
In conclusion, regional anesthesia is associated with an increased risk of acute postoperative urinary retention following midurethral slings in the ambulatory setting. This risk should be considered and incorporated into patient counseling regarding postoperative expectations.